31 Replies Latest reply on Mar 10, 2012 2:57 PM by ChristianAaltonen

    Maximum value of cmyk sum

    ChristianAaltonen Level 1

      Hi guys,

       

      because my last prints was too dark, I have to lighten the images a bit. Using eyedropper I sampled a refferrence spot from original image. The CMYK values are: 76+74+61+90 = 301. This "black" was too dark. It erased all the details. I need to get idea about the "maximum black" possible in ordinary print process, to find out, whether my walue {301} is really close to "absolute black" or the problem is somewhere else.

       

      Tell me please: What is the CMYK sum value for usual darkest black? Is it somewhere between 300 – 400? Which value shouldn't be exceeded in ordinary print process?

       

      Thank you!

        • 1. Re: Maximum value of cmyk sum
          MW Design Level 4

          Depends on what your press, paper etc needs to be. Going for about 240% would be 60 40 40 100.

           

          If I need a really, really rich black and the press and paper can do it, I use 75 68 67 90.

           

          Mike

          1 person found this helpful
          • 2. Re: Maximum value of cmyk sum
            Peter Spier Most Valuable Participant (Moderator)

            It really depends on the printing process.

             

            A sheet-fed press with dryer might be fine at 350% total ink, particularly in isolated areas, 320% would be safer, and under 300% probably would print on almost anything. Did your printer give you a color profile to use? That should set the maximum ink in any conversions you do, but it would still be possible to deliberately create a darker color.

            1 person found this helpful
            • 3. Re: Maximum value of cmyk sum
              Rik Ramsay Level 4

              When it comes to maximum ink values, you need to ask your printer what their max is. Some printers can accept different levels depending on their press but some will also tell you a lower ink level to reduce the chance of something going wrong and/or a complaint going to the printer. More ink = wetter paper and the thinner the paper, the more chance of it messing up.

               

              I personally now have my ink limits in Photoshop set to 300% but I used to have it at 270% because the printer I used at the time required that value.

               

              As for rich black, there are many combinations you can have and although a full 300% mix will be the darkest possible (printer dependant), the difference between that and a 200% mix would be hard to spot by the naked eye. As such, I now use a mix of c40 m20 y20 k100 for most of my blacks.

              1 person found this helpful
              • 4. Re: Maximum value of cmyk sum
                ChristianAaltonen Level 1

                Peter Spier wrote:

                 

                It really depends on the printing process.

                 

                A sheet-fed press with dryer might be fine at 350% total ink, particularly in isolated areas, 320% would be safer, and under 300% probably would print on almost anything. Did your printer give you a color profile to use? That should set the maximum ink in any conversions you do, but it would still be possible to deliberately create a darker color.

                Hi Peter,

                 

                so mistake was on my side, because my "301 CMYK mix" was too dark... I used coated paper and ordinary offset print.

                 

                My printer told me, that he wants final data without ICC profile assigned. So That is all I know...

                • 5. Re: Maximum value of cmyk sum
                  ChristianAaltonen Level 1

                  MikeWenzloff wrote:

                   

                  Depends on what your press, paper etc needs to be. Going for about 240% would be 60 40 40 100.

                   

                  If I need a really, really rich black and the press and paper can do it, I use 75 68 67 90.

                   

                  Mike

                  Hi Mike,

                   

                  in this case it will be a coated paper and classic offset print.

                   

                  OK, your "really, really rich black" is 75+68+67+90=300. So if I had 301 in the darkest spot, it is obvious, that I did mistake, because I should lighten the photos a bit, because instead of "light black" I used your "really, really rich black".

                   

                  Thanks mate!

                  • 6. Re: Maximum value of cmyk sum
                    ChristianAaltonen Level 1

                    RikRamsay14 wrote:

                     

                    When it comes to maximum ink values, you need to ask your printer what their max is. Some printers can accept different levels depending on their press but some will also tell you a lower ink level to reduce the chance of something going wrong and/or a complaint going to the printer. More ink = wetter paper and the thinner the paper, the more chance of it messing up.

                     

                    I personally now have my ink limits in Photoshop set to 300% but I used to have it at 270% because the printer I used at the time required that value.

                     

                    As for rich black, there are many combinations you can have and although a full 300% mix will be the darkest possible (printer dependant), the difference between that and a 200% mix would be hard to spot by the naked eye. As such, I now use a mix of c40 m20 y20 k100 for most of my blacks.

                    Thank you Rik,

                     

                    I have to  talk with my printer about his black possibilities. I just asked him about target CMYK ICC.

                     

                    Thank you for your helpful reply!

                    • 7. Re: Maximum value of cmyk sum
                      Rik Ramsay Level 4

                      If you are supplying a PDF for print, you can export from InDesign as a PDF/X-1A which will not include your profile when sending to the printer. This tends to be the standard PDF format for regular print work.

                      1 person found this helpful
                      • 8. Re: Maximum value of cmyk sum
                        ChristianAaltonen Level 1

                        RikRamsay14 wrote:

                         

                        If you are supplying a PDF for print, you can export from InDesign as a PDF/X-1A which will not include your profile when sending to the printer. This tends to be the standard PDF format for regular print work.

                         

                        OK then,

                         

                        in that case it does not matter which CMYK profile I choose in Photoshop when converting from RGB?

                        • 9. Re: Maximum value of cmyk sum
                          Peter Spier Most Valuable Participant (Moderator)

                          No, no. You must convert to the correct profile. PDF/X-1a strips out the profile information becasue it is presumed that the conversion is already in the correct profile.

                          • 10. Re: Maximum value of cmyk sum
                            Rik Ramsay Level 4

                            As Peter says, Yes it does matter. Typically in the US printers work with the US SWOP v2 profile. In Europe they use FOGRA 27 (or 39). It's best to keep the profile consistent through all applications and all images/files. If unsure what profile to start with, ask the printer.

                            • 11. Re: Maximum value of cmyk sum
                              ChristianAaltonen Level 1

                              Peter Spier wrote:

                               

                              No, no. You must convert to the correct profile. PDF/X-1a strips out the profile information becasue it is presumed that the conversion is already in the correct profile.

                              OK then now it is clear!

                               

                              What is a practical different btw. PDF/X-1a 2001 and 2003?

                               

                              Thanks!

                              • 12. Re: Maximum value of cmyk sum
                                ChristianAaltonen Level 1

                                RikRamsay14 wrote:

                                 

                                As Peter says, Yes it does matter. Typically in the US printers work with the US SWOP v2 profile. In Europe they use FOGRA 27 (or 39). It's best to keep the profile consistent through all applications and all images/files. If unsure what profile to start with, ask the printer.

                                Perfect!

                                 

                                Now it is absolutely clear. I use FOGRA39 for EU. But I will ask him anyway.

                                 

                                Thank you!

                                • 13. Re: Maximum value of cmyk sum
                                  Rik Ramsay Level 4

                                  What is a practical different btw. PDF/X-1a 2001 and 2003?

                                   

                                  In the modern day, nothing. 2001 was based (supposedly) on Acrobat 1.3 whereas 2003 was based on 1.4. They both do the same thing in terms of output.

                                  • 14. Re: Maximum value of cmyk sum
                                    ChristianAaltonen Level 1

                                    RikRamsay14 wrote:

                                     

                                    What is a practical different btw. PDF/X-1a 2001 and 2003?

                                     

                                    In the modern day, nothing. 2001 was based (supposedly) on Acrobat 1.3 whereas 2003 was based on 1.4. They both do the same thing in terms of output.

                                    Perfect, tahnks!

                                     

                                    2003 will be probably the Choice!

                                     

                                    Thanks

                                    • 15. Re: Maximum value of cmyk sum
                                      Petteri_Paananen Level 4

                                      If your problem is that black areas in your images are too dark and details will be lost, it´s possible that problem is not with total inks or used profiles. You may have issues with the tonal range of your image. Normal 8-bit image has 256 tones, the darkest one (0) is pure black  and lightest one (255) is pure white. The problem is that regular printing process can not separate first few (0-3) and last few (252-255) tones. So if you have details in the black area of your image, some of them tone 0, some of them tone 1 some of them tone 2 etc... printing process will blend them together and you will lose details in dark areas. If you want to avoid that, you may have to adjust the black and white point of your image. If you set your black point (the darkest value in your image) to 3 instead of 0, printing process may handle dark areas better.

                                      • 16. Re: Maximum value of cmyk sum
                                        rob day Adobe Community Professional & MVP

                                        Also, the Black Point Compensation and Intent choices can have a significant impact on CMYK conversions. Here you can see unchecking BPC with Relative Colorimetric produces a separation where everything over 90% separates to the total ink max, but with BPS I get separation between 90%, 95%, and 100%:

                                         

                                        nbpc.png

                                         

                                        bpc.png

                                        • 17. Re: Maximum value of cmyk sum
                                          ChristianAaltonen Level 1

                                          Petteri_Paananen wrote:

                                           

                                          If your problem is that black areas in your images are too dark and details will be lost, it´s possible that problem is not with total inks or used profiles. You may have issues with the tonal range of your image. Normal 8-bit image has 256 tones, the darkest one (0) is pure black  and lightest one (255) is pure white. The problem is that regular printing process can not separate first few (0-3) and last few (252-255) tones. So if you have details in the black area of your image, some of them tone 0, some of them tone 1 some of them tone 2 etc... printing process will blend them together and you will lose details in dark areas. If you want to avoid that, you may have to adjust the black and white point of your image. If you set your black point (the darkest value in your image) to 3 instead of 0, printing process may handle dark areas better.

                                          Thank you Petteri,

                                           

                                           

                                          OK then, that would mean, that pushing sliders in the Level dialog a bit would be the solution. But when I tried it, I thing that the final result is so slight, that maybe a more radical adjustment using Curves dialog would be better. If you would like have a look at my linked image, I would be pleased. { 16MB }

                                           

                                          http://dl.dropbox.com/u/16077473/Forums/Adobe/Ps/TR_Lotta_cerna-fialkova.psd

                                           

                                          Thank you!

                                          • 18. Re: Maximum value of cmyk sum
                                            ChristianAaltonen Level 1

                                            rob day wrote:

                                             

                                            Also, the Black Point Compensation and Intent choices can have a significant impact on CMYK conversions. Here you can see unchecking BPC with Relative Colorimetric produces a separation where everything over 90% separates to the total ink max, but with BPS I get separation between 90%, 95%, and 100%:

                                             

                                            nbpc.png

                                             

                                            bpc.png

                                            OK, Rob,

                                             

                                            Black point compensation checked every time, when converting! But this IMG was convert from RGB already and I got just the final CMYK, so There is no chance to find out the process now. So the only solution I see is just put a new adj. layer on the top of the IMG with Curves or Levels, that will compensate darkes areas. Or is there any better way?

                                             

                                            If you would like have a look at my linked image, I would be pleased. { 16MB }

                                             

                                            http://dl.dropbox.com/u/16077473/Forums/Adobe/Ps/TR_Lotta_cerna-fialko va.psd

                                             

                                            Thank you!

                                            • 19. Re: Maximum value of cmyk sum
                                              Petteri_Paananen Level 4

                                              Hi

                                               

                                              That image was already converted to CMYK... I prefer level/curves adjustements to be made to RGB image. I don´t have a calibrated/profiled monitor here at home so I can´t say exactly how well adjusted that image was.

                                               

                                              What comes to setting black/white points, moving those sliders in levels or curves dialog is sure one way to do that but I don´t use that so much myslef. First thing I always use to say in my color management courses is that calibrate your photoshop tools properly before you start to adjust images.

                                               

                                              1) Make sure that your eyedropper is set to take sample from 3x3 area, not point sample

                                              2) Set your eyedroppers black/white point target values to 0 > 3 (black) 100> 98 or 97 (white) (just double-click eyedropper icon in curves or level window and change L-value)

                                               

                                              After that you can use eyedropper with levels or curvers dialog to set black/white point (small white, grey and black eyedropper icons in level and curves dialog). Just activate white eyedropper and click the whitest spot in your image... and the darkest spot with black eyedropper.

                                               

                                              Another subject is to know where you will find darkest and lightes spot in your image, there you can use for instance threshold-tool.

                                               

                                              And of course

                                              3) Make sure that your color management settings are correct, defautl values are usually not the most optimized...

                                               

                                              After that you can start to adjust your images. And one more thing; calibrate and profile your monitor, otherwise those previous steps may even be worthless.

                                              • 20. Re: Maximum value of cmyk sum
                                                Peter Spier Most Valuable Participant (Moderator)

                                                Here's a totally different technique that you can try.

                                                 

                                                Make a copy of the current layer, then go to Image > Adjustments > Shadow/Highlights...

                                                 

                                                This behaves similar to adding a Shadow/Highlight adjustment layer (which is not available). You can adjust the shadow slider to decrease the effect, but becasue it is a separate layer, you can overadjust without fear and change the opacity of the new layer to tweak how it is applied. You can even use a layer mask to do finer adjustements.

                                                • 21. Re: Maximum value of cmyk sum
                                                  rob day Adobe Community Professional & MVP

                                                  Check your link it's throwing a 404 error.

                                                  • 22. Re: Maximum value of cmyk sum
                                                    Peter Spier Most Valuable Participant (Moderator)

                                                    Rob, the first reference to the link a couple of posts up seems to work (it did for me).

                                                    • 24. Re: Maximum value of cmyk sum
                                                      rob day Adobe Community Professional & MVP

                                                      It erased all the details.

                                                       

                                                      By details do you mean the pattern on the shirt, or the tonality of the fabric. The fabric tonality is pretty much non existent, so I don't think there's much you can do to retrieve it, but you could get at the pattern via selective color and USM. Something like this:

                                                       

                                                      Screen shot 2012-03-10 at 1.23.59 PM.png

                                                      Screen shot 2012-03-10 at 1.22.28 PM.png

                                                       

                                                      Screen shot 2012-03-10 at 1.23.33 PM.png

                                                      • 25. Re: Maximum value of cmyk sum
                                                        rob day Adobe Community Professional & MVP

                                                        It might help to add a manual trap in PS via Edit>trap.. which will spread the magenta and yellow into the black.

                                                        • 26. Re: Maximum value of cmyk sum
                                                          ChristianAaltonen Level 1

                                                          Peter Spier wrote:

                                                           

                                                          Here's a totally different technique that you can try.

                                                           

                                                          Make a copy of the current layer, then go to Image > Adjustments > Shadow/Highlights...

                                                           

                                                          This behaves similar to adding a Shadow/Highlight adjustment layer (which is not available). You can adjust the shadow slider to decrease the effect, but becasue it is a separate layer, you can overadjust without fear and change the opacity of the new layer to tweak how it is applied. You can even use a layer mask to do finer adjustements.

                                                          Hey, Peter,

                                                           

                                                          this is also nice technique! It is a pitty, that there is not adjustment layer for this – it will increase the filesize, but it does not matter.

                                                           

                                                          Thank you!

                                                          • 27. Re: Maximum value of cmyk sum
                                                            ChristianAaltonen Level 1

                                                            rob day wrote:

                                                             

                                                            It erased all the details.

                                                             

                                                            By details do you mean the pattern on the shirt, or the tonality of the fabric. The fabric tonality is pretty much non existent, so I don't think there's much you can do to retrieve it, but you could get at the pattern via selective color and USM. Something like this:

                                                             

                                                            Screen shot 2012-03-10 at 1.23.59 PM.png

                                                            Screen shot 2012-03-10 at 1.22.28 PM.png

                                                             

                                                            Screen shot 2012-03-10 at 1.23.33 PM.png

                                                            Thank you for your analysis Rob,

                                                             

                                                            the main problem was the tonality of the shirt, wich, as you said, is non existent. But i will try to fix the patten at least.

                                                             

                                                            Thanx!

                                                            • 28. Re: Maximum value of cmyk sum
                                                              Peter Spier Most Valuable Participant (Moderator)

                                                              I use this method all the time to open up the shadows and reveal detail that might otherwise be lost. I totally agree that a real adjustment layer would be nice, but by doing the adjustment to a duplcate layer you still are working non-destructively and maintaining the ability to change the image without reworking.

                                                               

                                                              Here's your sample file after a VERY fast and dirty adjustment. I added the layer mask to protect the reds, and if you turn the adjusted layer on and off you'll see the value hasnot changed for marker #3 in the red flower. The Threshold layer was to identify the darkest area, which turns out to be under the left arm, around marker #1. The way it is currently set I have reduced the total ink in the darkest areas around 15%.

                                                               

                                                              https://www.yousendit.com/download/M3Btb3BBT01UME43czhUQw

                                                              • 29. Re: Maximum value of cmyk sum
                                                                ChristianAaltonen Level 1

                                                                Thank you Perer for sharing your workflow!

                                                                 

                                                                Perfect way to achieve a nice results!

                                                                 

                                                                Do you have a second to have a look at my file on ce more? I set three layer comps for your convenience. Is any major different when using your system, which you described abowe and simple Curves adjustment layer, which I set in this linked file?

                                                                 

                                                                http://dl.dropbox.com/u/16077473/Forums/Adobe/Ps/TR_Lotta_cerna-fialkova02.psd

                                                                • 30. Re: Maximum value of cmyk sum
                                                                  Peter Spier Most Valuable Participant (Moderator)

                                                                  On screen there is visually very little difference between your curves adjustment and my shadow/highlights adjustment, and if you look at the numbers for markers 1,  2 & 4 when you switch between the layer comps (open up the info panel) you'll see they are very close.  I think though, that if you increase the opacity of my layer you'll see more differences overall in the appearance if you also adjust your curve for similar readings in the midtones at #4. You may need to clean up the mask, by the way, to remove some splotchiness that is going to creep in as the effects are magnified. I was working fast and I used the magic wand to select the blacks instead of selecting the reds when I made the mask originally, and that probably wasn't a particularly good idea.

                                                                   

                                                                  Neither of the adjustments is huge as they stand, so it's not surprising that they look very similar. It's just one more technique.

                                                                  • 31. Re: Maximum value of cmyk sum
                                                                    ChristianAaltonen Level 1

                                                                    Thanks for your time Peter